In order to satisfy the further improvement of new communication equipment, filling the ridge grooves on side walls with fillers is the effective method to improve the quality of double-ridged rectangular bent tube in H-typed rotary draw bending. However, how to choose appropriate material filling in ridge grooves to reduce deformation more effectively is a critical issue. Therefore based on the reliable FE models of H-typed rotary draw bending and twice-springback of double-ridged rectangular tube with fillers with different material parameters, a selection criterion of the material of filler to minimize the cross-sectional deformation of bent tube was studied. The selection criterion is that only the height size accuracy of filler should be made sure to be consistent with that of the ridge groove. The strength coefficient K of filler should be considered firstly, and the larger K can reduce the deformation more effectively. The yield strength σs and hardening exponent n can be considered secondly, and filler with higher σs or smaller n can be selected as far as possible. Elastic modulus E may not be taken into account. The reliability of this selection criterion is verified by using 65Mn spring steel filler.